Rubbing machine



Feb. 18, 1930. sc 1,747,396

RUBBING MACHINE Filed May 31. 1922. 4 Sheets-Sheet 1 Howard B. Scott H.B. SCOTT RUBBING MACHINE Feb. 18, 1930.

Filed May 51. 1922 4 Sheets-Sheet 3 Howard B. Scott Feb. 18, 1930. H. B.SCOTT 1,747,396

RUBBING MACHINE Filed May 51. 1922 4 Sheets-Sheet 4 FIG.1O

A34 A32 A38 a 8a 8/ 8.4 A

Patented Feb. 18, 1930 UNITED STATES PA-TENT OFFICE HOWARD .B. SCOTT, OFDAYTON, OHIO, ASSIGNOB, BY MESNE ASSIGNMENTS, TO THE NATIONAL CASHREGISTER COMPANY, OF DAYTON, OHIO, A CORPORATION OF MARYLAND RUBBINGMACHINE Application filed May 31,

This invention relates to portable rubbing machines and the like,particularly adapted for use in finishing varnished surfaces of eithermetal or wood which require rubbing with pumice, abrasive paper orcloth, or some similar material as a step in the finishing operation. I

One object of this invention is to provide a small, light, compact,high-speed machine which will have the functions above mentioned andwhich will provide a more efficient means of accomplishing the desiredresults than anything now in use.

Another object of the invention is to provide a machine which will bepractically impervious to the dust and grit incident to the operation ofa device of this kind.

It is not desired to limit the invention to the above usage, as it isapparent that it can be used for a variety of brushing, burnishing,bufllng, polishing or sanding operations.

With these and incidental objects in view, the invention includescertain novel features of construction and combinations of parts, theessential elements of which are set forth in appended claims, and apreferred form or embodiment of which is hereinafter described withreference to the drawings which accompany and form part of thisspecification.

Of said figures:

Fig. 1 is a perspective view of the complete machine.

Fig. 2 is a detail isometric view of mem-v bers which connect thepistons with the rub hing pads, one of said members being shown insection.

Fig. 3 is a detail isometric view of one o the pistons.-

Fig. 4 is a view in side elevation of the device with the top plate andthe side plate removed some of the mechanism being shown in section.

Fig. 5 is a detail plan view of the bearing plate which is adapted toprevent any binding of the piston in the cylinder by reason of downwardpressure exerted by the operator.

Fig. 6 is a sectional view showing the main inlet valve, and is taken onthe line 6-6 of Fig. 4, looking in the direction of the arrows.

Fig. 7 -is a view in end elevation with the 1922. Serial 1T0. 564,774.

end plate removed and some of the parts broken away for the sake ofclearness.

Fig. 8 is a sectional view' taken through the machine on the line 8-8 ofFig. 10.

Fig. 9 is a top plan view of the machine with the cover plate removed.

Fig. 10 is a longitudinal sectional view taken on the line 1010 of Fig.9, looking in the direction of the arrows.

Fig. 11 is a horizontal sectional view taken on the line 11-11 of Fig.8, looking in the direction of the arrows.

In general, the form selected to illustrate one embodiment of theinvention, includes a body portion having parallel cylindrical holesbored therethrough from end to end, the larger bore constituting a motorcylinder, ind the smaller bore a Valve chamber there- Two double-headedpistons are arranged to traverse the cylinder, the pistons reciprocatingsimultaneously towards and from each other.

To accomplish this, valve mechanism in the smaller bore is controlled byone of the pistons to admit air pressure or other motive fluidalternately between the pistons to force the pistons apart, and then tothe ends of the cylinder to drive the pistons towards each other.

Provision is, of course, made to exhaust the spent fluid from in frontof the pistons.

Fastened to each piston is a member which carries a ruhbingxpad of feltor any other suitable material which is rapidly reciprocated by theaction of the pistons to perform the rubbing operation. The memberscarrying the rubbing pads are connected to each other in such a manneras to synchronize their movement. And in order to prevent as far aspossible the entry of dust, dirt and other extraneous material incidentto the operation of the machine, to the working parts thereof, themechanism has been enclosed in a casing, and the ports so arranged as todirect the exhaust into this casing and out through the slots formedtherein. This not only operates to prevent the entry of dust, but also'expels that which may have worked its way into the casing.

Fast to each end of the body portion A (Fig. 11) of the device are twoplates 45 and 46 (Fig. 1), which are held'in position by means of screws47 and which close the ends of longitudinally extending operatingcylinder 74, and valve chamber 71, respectively. A top plate 48 isfastened to the body portion 'A by long screws 49 (Fig. 7), the contourof said plate being formed to fit the palm of the hand of the operator.

The upper edges of the end plates 45 and 46 extend above the top planeof the body portion A, and the top plate 48 fits closely between the endplates to exclude dirt and similar material.

The side edges of the end plates 45 and 46, as well as the side edges ofthe top plate 48, extend beyond the sides of the body portion A, theunder face of such projecting edges of the top plate being grooved, asare also the projecting side edges of the end plates and 46, toaccommodate the top and end edges of two casing plates 50 extend- .ingalon and covering the sides of the body UOntmZ wake The air or othermotive power, under pressure, is brought to the device through anysuitable flexible tubing which is connected to an upwardly extendingnipple 54 (Fig.

1 10), formed integral with the end plate 45. V The nipple 54 containsan inlet passage 55 chamber 57 open at both ends and extend- (Fig. 6),which conducts the pressure to the main control valve mechanism. Thiscontrol' valve mechanism includes a plunger 56 (Fig 6) slidably mountedin a cylindrical ing across the end plate 45. This plunger 56 isprovided with two heads. 58 and 59 spaced apart and normally located onopposite sides of the juncture of the passage 55 with the chamber 57,-to prevent the escape a of pressure when the valve is inits closedposition, as shown in Fig. 6. A spring 60, one end of which is seated ina long seat formed in the right hand end of the plunger 56, and theother end of which bears against I 'a pin or abutment 61 extendingacross the adJacent open exhaust end of the chamber 57',

tends to force the plunger 56 toward the left (Fig. 6) in order to keepthe valve closed.

When it is desired to open the valve, the

plunger 56 is moved toward the right (Fig.

i 6) by means of a lever 62 (Figs. 1 and 9), pivoted at-63 in aguideslot in the top plate 48.

Slotsare cut in the walls of the valve chamber 57 (Fig. 1) at one end topermit the lever 62 to completely open the valve. The opposite end ofthe lever 62 is pro vided with a cam portion 64, which, when the valveis closed, abuts against the wall of the guide slot formed in said topplate, (Fig. 9) and thereby limits the spring-actuated movement ofplunger 56 toward the left (Fig. 6). The lever 62 carries a cap screw 65which limits the'movement of the lever toward the right. This screw canbe adjusted to vary the amount of pressure admitted to the machine,which will, of course, control the speed at which it operates.

When the control valve is closed and the plunger 56 is returned to itsleft hand position, as shown in Fig. 6, the head 59 uncovers the end ofa passage 66 which conducts the pressure through various valve chambersto be later described,,to the main operating cylinder. This permits theexhaust which is at this time under pressure in the machine, to escapethrough the right hand end of the chamber 57 into the atmosphere. Thisrapid reduction of the pressure is necessary to prevent the pistonsfrom, stopping in the middle of their stroke, in which position theywould not start. I

Air intake I I When the control valve plunger 56 is moved toward theright (Fig. 6) by the lever 62, as a A above described, the head 59uncovers the end of the passage 66 to permit the motive fluid from theinlet 55 to enter passage 66, which leads downward and joins ahorizontal passage 67 (Figs. 6 and 11) extending longitudi nally of thebody portion of the machine alongside the valve chamber 71. A valvebushing 70 (Fig. '10) is fixedly located in the valve chamber 71,intermediate its ends, the bushing, preferably having three peripherallyextending grooves 69, 73, and 82 formed 1 exteriorly thereof, andseparate from each other. 7 These grooves are separated from each otherby theintervening unreduced portions of the valve-bushing. The groove 69forms a pressure inlet chamber, and the grooves 73 and 82 each form acombined inlet and exhaust chamber, annular in shape, each of which isconnectedby an annular row of ports with the hollow interior of the'valve bushing. I Thus annular series of ports 108 and 83 connect theannular chambers 73 and 82, respectively, with the interior chamber of.the valvebushing.

The annular pressure inlet preferably wider than the remaining annularchambers, and is provided. with two annular f rows of ports 72 and105,-respectively, located near the opposite ends of the chamber 69, andcommunicating with the hollow interior of the valve bushing 70. I

A valve having three heads 88,89 and 90 chamber 69 is I alined upon asingle valve stem 87, is slidably mounted Within the valve bushing, theintermediate head 88 being longer than the two remaining heads 89 and90, to cover one or the other annular series of ports 72 or 105 leadingfrom the annular pressure inlet chamber 69 to the internal chambers 84and 710 into which the hollow interior of the valve bushing is dividedby the intermediate valve head 88. A large port 68 admits pressure fromthe passage 67 to the annular pressure inlet chamber 69.

A combined inlet and exhaust port 75 passing through the wall of thebody portion between the combined inlet and exhaust chamber 73 and thepiston cylind'er74 at a point substantially midway between the ends ofthe cylinder 71, afi'ords direct communication between the annularchamber 7 3 and the piston cylinder.

Combined inlet and exhaust ports 79 formed in the ends of the bodyportion A (Figs. 7 and 10) lead from the opposite ends of the pistoncylinder 74 to the opposite ends of a combined inlet and exhaust passage80 extending longitudinally through the body portion A from end to endthereof (Fig. 11), the ends of the passage 80 being closed by the endwalls 45 and 46.

The passage 80 lies in substantially the same horizontal plane with theinlet passage 67, but along the opposite side of the body portion A, andis equipped with a port 81 (Fig. 11) communicating with the annularinlet and exhaust chamber 82.

The intermediate valve head 88 controls the two series of ports 72 and105 between the annular pressure inlet chamber 69 and the internalchambers 710 and 84 within the valve bushing, and the heads 89 and 90control communication between the internal chambers 710 and 84 and theopposite ends of the valve chamber 71, by covering or uncovering thecastellated openings 85 and 107 formed in the opposite ends of the valvebushing, respectively.

A plurality of exhaust ports 86 and 109 lead from opposite ends of thevalve chamber 71, the large number of small ports shown being for thepurpose of mufiing the noise of. the exhaust.

Cylinder and pistons As stated in the general description, the

machine has a single cylinder 74 in which operate two driving pistons 76(Fig. 10) arranged in tandem in the cylinder. These pistons are of thedouble head variety and each head is grooved to accommodate a ring 77 ofconventional design held against peripheral rotation by a pin 78 whichprojects into a slot in the ring. The pistons are adapted to reciprocatein opposite directions towards and from each other in the cylinder dueto alternating periods of pressure and ex- Valve operating mechanism Thevalve heads 88, 89 and control the opening and closing of the intake andexhaust ports. The central head 88 of the three controls the intake offluid to both the center and the .ends of cylinder 74, the right handhead 89 controls the exhaustion of fluid from the ends of the cylinder74, and the left-hand head 90 controls the exhaustion of fluid frombetween the pistons 76. The stem 87 of the valve has an extension 91apertured to surround a ball 92 at a point about midway of the length ofa lever 93. At its lower end this lever passes through an openin in thewall of the chamber 71, and carries a all 94 which rests in aseat/formed in a cap 95 screwed to the bottom of the main body portionA. The cap 95 acts as a fulcrum for the lever 93. At its upper end, thelever 93 passes through an elongated opening in the wall between thevalve chamber ,71 and the piston cylinder 74,

and carries a head 101 cupped to surround a ball 102 formed. on thelower end of a screw 103 which extends through the center of one of thepistons 76 and whose function will be hereinafter described. A spring104 located in the bottom of the seat in the cap 95 tends to keep thelever 93 engaged with the ball 102 on the piston. I

'It can be seen, therefore, that through the above describedconnections, the lever 93 will be rocked backward and forward with andby the piston 76 to which it is connected and as the valve stem 87 isconnected to the lever 93 by a universal joint, it will be reciprocatedalso for the purpose of opening and closing the valve at the correcttime.

The following description of the operation assumes that at the time whenthe power was previously shut off by the manually-controlled valve 56,58, 59, (Fig. 6) the parts came to rest in the positions shown in Figs.10 and 11. i

When the operator is ready to use the machine, he' places his hand onthe formed top plate, his fingers falling naturally into the properpositions with the horn 40 in the space between the thumb andforefinger, the forefinger lying in the curved finger piece 41 on thecontrol lever 62.

Then by simply gripping the machine in the ordinary manner to lift itonto the work, the tension thus exerted rocks the control lever 62, thefree end of which presses against the projecting end of the lunger 56 toslide the control valve to the rig t (Fig. 6) against the tension of therestoring spring 60, until the head 59 uncovers the adjacent end of thepassage 66, thereby permitting the pressure from the inlet 55 to enterthe passage 66.

The passage 66 conducts the pressure to passage 67 whence it is ledthrough port 68 (Fig. 11) to the annular pressure inlet chamber 69.

The intermediate valve head 88 blocks the annular series of ports 105leaving the annular series of ports 72 uncovered. Hence thepr-essure'passes through the ports 72 into the internal chamber 710formed in the valve bushing 7 0 between the intermediate head 88 and theend head 90. The head 90 covers the cast-ellat-ions 107 in the left-handend (Fig. 11) of the valve bushing70, so that the pressure can onlyescape from the internal chamber 710 through the annular row of ports108 into the annular combined inlet and exhaust chamber 7 3 (nowfunctioning as an inlet chamber) (Figs. 11 and 10) and thence, throughthe large port 75 to the space between the independent pistons 7 6, inthe cylinder 71, where it operates to drive the pistons in oppositedirections towards the opposite ends of the cylinder 74.

The fluid from the exhaust ends of the pistons 76, escapes through theexhaust ports 79 (Figs. 10 and 7) at the opposite ends of the cylinder,to the longitudinal passage-80 (Fig. 11) and thence, through the largeport 81 into the annular tombined inlet and exhaust chamber 82 (nowfunctioning as an exhaust chamber) of the valve bushing, and through theannular row of ports 83 to the internal chamber 81 formed between theheads 88 and 89 of the slide valve.

The head 89has uncovered the castellated ports in the. right-hand end(Fig. 11) of the valve bushing, so that the exhaust escapes from theinternal chamber 84 through the ports 85 into the right-hand end (Fig.11) of the valve chamber 71 and thence, through the mufii'ing ports 86.As these mufliing ports 86, as well as muflling ports 109 hereinafterreferred to, are formed on both sides of the valve chamber 71, theexhaust passes therethrough into the space between the body portion A ofthe machine, and the casing plates 50 on both sides of the machine, andthence through the slotted openings 52 in the filler bars 51 downtowards the work. I

By directing the exhaust downwardly in this manner, the dust and dirtincident to the operation of the machine is prevented, in great measure,from entering the machine and clogging or injuring the parts.

Particularly is this desirable when working with pumice or other fineabradant material, which is dispersed by the operation of the machine onthe work and if allowed to enter the machine, and especially the valveand piston chambers, would quick y cause undesirable wear of the partsand great damage to the machine.

Reverse movement of pistons connections 93 with one of the pistons,slides the intermediate head 88 over the inlet ports 72, and therebycuts 'oii' the supply of pressure. from the annular pressureinletchamber 09 through ports 7 2, internal chamber 710, ports 108,annular inlet and exhaust chamber 73 to the port 75 between the pistonsand also shifts the right-hand head 89 to cover the castellated exhaustports 85 in the valve bushing 70, leading from the internal chamber 8-1to the adjacent end of the valve chamber'71; and simultaneously shiftsthe opposite head 90 to uncover the castellated exhaust ports 107leading from the internal chamber 710 to the valve chamber, therebypreventing the exhaust through eastellated ports 85, and permittingexhaust through ports 107. Almost at the same time the in termediatehead 88 uncovers the annular row o'f'ports 105 leadingfrom the annularpressure inlet chamber 69 to the internal chamber 8+1 and the pressureis thereby/permitted to pass from thischamber, through the ports 83 intothe annular inlet and exhaust chamber 82, (now functioning as an inletchamber) then through port 81 (Fig-11), air passages 80. and ports 7 9to both ends of the piston cylinder 7 a to drive the pistons 76 towardthe center.

This permits the exhaust pressure which is between the pistons 76 to beexpelled through the central port 75, annular inlet and exhaust chamber7 3 (now functioning as an exhaust chamber), ports 108, internal chamber710 and the openings 107 in the castellated end of valve bushing 70, tothe valve chamber 71 whence it exhausts through the multiple eX- haustopenings 109 in the body portion A of the machine. Thus the cycle ofoperation of the pistons 7 6 is completed and they are returned to thepositions in which they are shown in Fig. 10.

Rubbing paid carriers The pistons 76 as they move towards and ed'lugs112 (Fig.4) which project from said shoes. This method of mounting thepads greatly facilitates their replacement when this becomes necessary.

These pads and, shoes are reciprocatedby the pistons 76 and are directlyconnected thereto by means of inverted U-shaped members 114, (Figs. 2,4, 7, 8, 9, 10 and 11) each comprising a pair of legs connected at theirupper ends by a flat web. At their lower ends these legs embracethe sideedges of and are screwed to the pad-carrying shoes 111. Extendingdownwardly from the connecting webs of each of the U-shaped members aretwo spaced lugs 115 and 116 (Figs. 2, 8 and 10) which are adapted to fitinto' vertical channels 117 formed on each side of the center of thepistons 76, between the heads thereof (Fig. 3). The screw 103 and asimilar screw 118 (Fig. 10) pass through countersunk holes 119 in theconnecting webs to secure the members 114 rigidly with the pistons.

To permit connection of the spaced lugs 115, 116 with their respectivepistons 76, the lugs depend through elongated openings 741 (Figs. 8 and10) extending longitudinally through the upper wall of the body portionA into the upper side of the piston cylinder, such openings lyingbetween the heads of each piston and being of less length than theoverall length of the pistons so as to remain covered thereby at alltimes.

The lug and channel connection between the connecting webs 114 andpistons 76 permits the connections 114 to have vertical movementrelatively to the pistons, so as to relieve the pistons of the thrustcaused by the weight of the machine and such pressure as may be appliedby the operator in using the machine, which thrust is transmittedthrough the shoes to the connecting members.

The under faces of the flat connecting webs between the legs supportingthe shoes 111,

extend over the flat upper face "120 of the body portion A, and slidehorizontally between the top surface 120 of the main body portion and areplaceable bearing plate 121 (Figs. 4 and 5) which is supported on foursmall spacing blocks 122, one at each corner of the top face 120 of themain body portion. This bearing plate 121 is held in place by fourscrews 49 which extend through the spacing blocks 122 into the bodyportion, as shown in Fig. 7, and also serve to secure the top plate 48in place. The bearing plate when worn, may be replaced by a new platewithout necessitating replacement of the body portion A, or the topplate 48.

The function of the bearing plate 121 is to form a thrust surface withwhich the upper faces of the horizontal portions of the U- Y shapedmembers 114 contact to thereby lessen the wear on the upper half of thepiston cylinder 74 which would otherwise occur if the pistons 76 had totake the upward pressure created when the operator presses down on thedevice.

By mounting the rubbing pads or feet 111 in such relation to the pistons76 to which they are respectively connected that the centre of the footlies in the same perpendicular lme with a pomt midway between the endsof its piston, vibration ofthe parts is reduced as well as the tendencyotherwise present, to cook or tilt the piston.

Synchronizing mechanism It is essential to the smooth operation of thedevice that the pistons be connected for synchronous operation. This isaccomplished by the following means. The adjacent edges of thehorizontal webs of each of the U-shaped members 114 is complementarilystepped (F 1 2) and has rigidly fastened to its fart est advanced step,a guide lug 124 from which projects a stud 125 (Figs. 2 and '4). Thesestuds pass through guide slots 126 (Fig. 5), in the bearing plate 121,which slots embrace the guide lugs 124 to hold the connecting members114 to a rectilinear movement. The upper ends of the studs 125 haveloosely mounted thereon slides 127 (Figs. 4 and 9)" which rest on thebearing plate 121. These slides 127 are embraced by slots 128 out in theopposite ends of a rocker 129 which has a, centrally located hub 130(Fig. 10) projecting downwardly through a hole 131 in the stationarybearing plate 121, the lower end of the hub 130 passing between thestepped edges of the connecting members 114 and resting on the top face120 of the main body portion of the machine. Projecting downwardlyinside of the hub 130 is a pivot pin 132 the upper end of which has acircular cap flange 133 integral therewith and fastened to the underrecessed face of the .top plate 49 by screws 134.

the pistons are reciprocated as above described, the studs 125 carriedby the U-shaped connecting members 114 will cause the slides LubricationThe pistons are lubricated b means of a steam engine lubricator (not sown) which injects a small quantity of oil into the air stream atpredetermined intervals, by which it is carried to the cylinder.

The top surfaces of the horizontally reciprocated U-shaped connectingmembers 114 are lubricated by means of oil dropping through two oilholes 135 (Figs. 5 and 10) in the bearing plate 121. The oil isdistributed by oil grooves 136 in the under face of the bearing plateleading from the oil holes 135. The oil can be supplied to the oil holes135 from reservoirs formed in the under face of It is apparent from theabove that when and described is admirably adapted to fulfill theobjects primarily stated, it is to be understood that it is not intendedto confine the invention tothe one form or embodiment herein disclosed,for it is susceptible of embodiment in various forms all coming withinthe scope of the claims which follow. What is claimed is: 1. In a fluidpressure motor, the combination of-a cylinder, a pair of oppositelyacting pistons therein, a member driven by each of.

said pistons and attached thereto midway of its length a stud carried byeach of said members, a plvoted rocker having] slots formed therein, andslides surrounding said studs and adapted to shift in the said slots ofsaid rocker to co-operate therewith to enforce a simultaneous andco-extensive movement of said plstons. p

2. In a fluid pressure motor, the combination of a cylinder, two pistonsoperating in the cylinder,and power transmitting members for saidpistons extending parallelly therefrom, synchronizing means comprisingan element pivoted at a point intermediate of said members and providedwith radially extending slots, and slides carried by said membersoperating in said slots.

3. In a fluidpressure motor, a piston, a power transmitting member, avalve operatingmeans, means for securing said power transmitting memberrigidly to said piston, and means on said securing means connected withsaid valve operating means to actuate the latter.

4. In a fluid pressure motor, a piston, a power transmitting memberextending laterally from one side of said piston, a valve located on theother side of said piston, and a bolt to rigidly connect said piston andpower transmitting member, and extending through said member and pistonand projecting beyond the side of said piston to operate said valve.

5. In a fluid pressure motor, the combination with a body portion havinga cylinder formed therein; of a piston in the cylinder; the pistonhaving channels extending transversely thereof intermediate its ends;

"a power-transmitting member; connecting means between thepower-transmitting member and the piston, such connecting means looselyfitting in the channels to prevent relative movement between theconnecting means and piston axially of the piston, while permittingrelative movement between the connecting means and the piston in a d 1member; and a stationary bearing plate over the power-transmittingmember to afford a backing for the transmitting member.

6. In a fluid ressure motor, the combination with a ho y portion havinga cylinder formed therein; of a piston in the cylinder, comprising twoheads connected by a stem, the stem provided with vertically extendingchannels on its opposite sides; a power-transmitting member; spacedattaching lugs depending from the lower face of the powertransmittingmember and loosely fitting in the respective channels, to permitrelative movement between the piston and powertransmitting member; and aremovable bearing plate against the lower face of which the upper faceof the power-transmitting member bears, to limit such relative movement.

7. Ina fluid pressure motor, the combination with a body portion havinga single cylinder formed therein; of two double-headed pistons operablein opposite directions in the single cylinder; separatepower-transmitting means connected directly with the respective pistons,and arranged side by side, the powertransmitting means extending atright angles to the direction of travel of the pistons; andsynchronizing means between the two pistons, including a rockerpivotally mounted intermediate its ends and having slots formed in itsoppositely extending armsyconneCting means carried by the respectivepower-trans,- mitting members, and entered in the slots in the rocker,to enable the piston-driven powertransmitting members to oscillate therocker; and slides pivotally mounted on the connect-- ing means andadapted to traverse the slots in the-rocker.

8. In a fluid pressure motor, the combination with a body portion havinga cylinder, a valve chamber, and a duct formed therein; and pistonsoperating in the cylinder; of a valve bushing in the valve chamber,having an annular pressure inlet chamber formed exteriorly thereof, andan annular combined inlet and exhaust chamber located on each side ofthe pressure inlet chamber, one of the annular combined inlet andexhaust chambers having a port communicating with the cylinder at apoint between the pistons, the other of said annular combined inlet andexhaust chambers having a port communicating with the duct; the pistoncylinder having ports at its opposite ends communicating with the duct;the valve chamber having exhaust ports leading therefrom; the valvebushing having ports aflording communication between the severalexterior annular chambers and the in terior of the bushing; a valveslidable within the bushing and including an intermediate head andexhaust heads laterally spaced therefrom to divide the valve bushinginto two internal chambers the intermediate head adapted to control theadmission of pressure inlet from the annular pressure chamberalternately to the internal chambers of the valve bushing, the exhaustheads adapted to control the exhaust ports from the bushing to the valvechamber; and means operated by one of the pistons to operate the valve.

9. In a fluid pressure motor, the combination of a body portion havinga'cylinder, a valve chamber, and a combined inlet and exhaust ductformed therethrough from end to end, parallel with each other; endplates secured to the ends of the body portion and closing the oppositeends of the cylinder, the valve chamber, and the duct, and having portsformed on the inner faces thereof to connect the ends of the cylinderwith the ends of the duct; oppositely traveling pistons operating in thecylinder; a valve bushing located in the valve chamber and having anannular pressure inlet chamber formed exteriorly around the valvebushing. and an annular inlet and exhaust chamber formed exterior'lyaround the valve bushing on each side of the annular pressure inletchamber; the valve bushing having ports to afford communication betweenthe several exterior annular chambers and the interior of the bushing,and also having exhaust ports leading from the interior of the bushingto the valve chamber; the body portion having a port to affordcommunication between the piston cylinder at a point between thepistons, and one of the lateral y located annular chambers, and a portto afford communication between the inet and exhaust duct and the otherof the laterally located annularchambers; a valve slidable in thebushing and including a head to control the admission of pressure inletfrom the annular pressure chamber to the interior of the valve bushingwhen the valve is at either end of its limit of travel, and heads tocontrol the exhaust ports from the valve bushing to the valve chamber,the valve chamber having exhaust ports leading therefrom; and means toconnect the valve with one of the pistons to operate the valve.

10. In a fluid pressure motor, the combination of a body portion havinga single piston way extending parallel with the cylinder and valvechamber and having ports communicating with the ends of the-cylinder anda port communicating with the annular chamber on the opposite side ofthe annular pressure inlet chamber; the valve bushing having ports toafford communication between the several exterior annular chambers andthe hollow interior of the valve bushing, and between the interior ofthe valve bushing and the opposite ends of the valve chamber; the wallof the valve chamber having exhaust ports adjacent its opposite ends;means to admit pressure to the annular pressure inlet chamber; a valveslidable within the valve bushing, including a pressure inlet headlocated intermediate its length and exhaust controlling heads, one oneach side of, and spaced apart from, the intermediate head, toalternately cover and uncover the exhaust ports leading from the valvebushing; the intermediate valve head adapted to control the admission ofpressure from the annular pressure inlet chamber to either lateralannular chamber, as well as to control the passage of the exhaust fromin front of the ends of the oppositely traveling pistons, to eitherlateral annular chamber alternately with the admission of pressurethereto; and a connection between the valve and one of the pistons toshift the valve back and forth, and reverse the admission of pressureand exhaust of fluid alternately from end to end of the pistons.

In testimony whereof I aflix my signature.

- HOWARD B. SCOTT.

cylinder and a valve chamber formed therein,

the piston cylinder and valve chamber lying parallel with each other; apair of pistons adapted to travel towards and from each other in thecylinder; a valve bushing in the valve chamber having an annularpressure inlet chamber formed exteriorly of the bushing intermediate itsends, and two annular chambers formed exteriorly of the bushing, andlocated one on each side of the annular pressure inlet chamber; the bodyportion havm a a? piston chamber to connect the latter with the annularchamber on one side of the annular pressure inlet chamber; a passageportlocated intermediate the ends of

